The Tiffen Series 9 85C Color Conversion Filter helps to decrease the color temperature from 5500 to 3800K, allowing the use of tungsten-balanced film in daylight conditions. The warming effect of this filter requires a 0.3-stop increase in exposure for normal results.
This filter is made using ColorCore technology, a process that involves laminating the filter substrate between 2 pieces of optical glass, grinding flat to a tolerance of 1/10,000th of an inch, and then mounting to precision metal rings. It is compatible with Series 9 filter holders.
Color conversion filter decreases color temperature and provides a warming effect.
Converts 5500 to 3800K for using tungsten-balanced film in daylight conditions.
Filter factor of 1.3 requires a 0.3-stop increase in exposure.